Alternative Fic Metadata: Continuity, Quadrants, and Polyamory

As a Critical Role fan I would love a continuity/era-based system. Each CR campaign has an entirely new cast of characters; when I finished campaign one I wanted to go read fic, but it's almost impossible to sort by campaign on AO3 since very few people use the Additional Tags for that, so I was at constant risk of spoiling myself for campaign two. I'm sure many fans of anthology series have faced this problem.

Homestuck's quadrant romance system (♥, ♦, ♠, and ♣) all gets synned to "/" on AO3, so it's impossible to narrow your search to specific quadrants unless the authors clarify in the Additional Tags.

This got me thinking about an "A, B, x" tagging system, where A and B are characters and x is the type of relationship. (Or "A, B, C, x" "A, B, C, D, x", etc.) For most fandoms x would usually fall into the "family" "romantic" "sexual" or "platonic" bucket, while sci-fi fandoms with weird alien romances like Homestuck could tag and filter how they pleased. It would also leave room for evolving terminology; I'm sure "queerplatonic" would see some use.

"A, B, x" would be a subtag of the broader tag "A, B" as well as the broader tag "x", so you could search for a pairing regardless of their relationship, or a relationship type regardless of characters. Similarly, you could exclude specific relationship types from your search: "A, B" NOT "A, B, family" for example.

(This would naturally result in vicious discourse about which relationship category tags should be canonized. 🤷‍♂️)

Another idea is polyamory tagging that allows you to specify who in the polycule is dating vs. who's metamours (or who in the orgy is fucking vs. who isn't), without relying on twosome tags that are also used for non-polyship tagging.

Example: I write a fic where A gets doted on by their two partners, B and C, who aren't dating each other and whose dynamic as metamours is not remotely touched upon by the fic.

On AO3, I tag this as "A/B/C", "A/B", and "A/C"—and then I have to decide whether to tag "B&C". If I do, I'm clogging up the search results for people who want to read about B and C being friends. If I don't, I'm omitting metadata that's important to me as both a shipper and a polyamorous person: that A/B/C is not a triad in this fic.

Under this new hypothetical system, I tag "A/B/C", and then I'm prompted to specify who within that trio is actually dating. The fic is thus also tagged with "A/B | A/C | B&C" which is a subtag of "A/B/C" but not a subtag of any twosome tags. I add twosome tags only at my own discretion: in this case, "A/B" and "A/C", since the fic focuses on those sides of the triangle.

Maybe this is too complex to realistically implement, but it's a fun dream.